Tag Archives: low pressure

NYC Weather Update – Apr 19, 2021

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A week of contrasts is in store, starting with warm, above average temps in the 60s and 70s Monday and Tuesday, then rain coming mid-week, caused by a vigorous cold front. Behind this, temperatures will plummet to below normal in the low-50s by Thursday. There are rain chances Monday afternoon with scattered showers and thunderstorms and more substantial chances Wednesday.

Rest of today – starting off sunny, with highs climbing into the mid-60s. Later in the afternoon, clouds develop with a shortwave moving through the area. This mid-level disturbance could see some scattered showers and thunderstorms. Overnight lows in the upper-40s with clearing skies.

HRRR model simulated radar valid for 6 PM this evening. Some scattered showers and thunderstorms are possible especially inland north and west.

Tuesday – best day of the week with high temperatures rising into the low-70s under sunny skies ahead of the incoming storm Wednesday. Overnight lows in the low-50s.

Wednesday – rain chances increasing during the day into the overnight hours. High temperatures in the low-60s under mostly cloudy skies. Behind the frontal boundary bringing the rain, strong cold air advection kicks in, dropping lows into the upper-30s.

Weather Prediction Center surface forecast for 8AM Wednesday. A low pressure center will be progressing through the region bring through a cold front, showers and scattered thunderstorms.

Thursday – sunny in the morning with more clouds developing in the afternoon. With a cold start, high temperatures only hitting the low-50s. Overnight lows dropping to the low-40s.

NYC Weekend Weather – Apr 16, 2021

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A steady warming trend takes place this weekend on the heels of a late season snow storm for interior New England. Temperatures will go from below normal in the low-50s to about average for this time of the year in the low-60s. High pressure brings us decent conditions but rain chances are not out of the question Sunday and Monday with some mid-level disturbances possibly bringing some showers.

Rest of today – wraparound moisture from a late-season Nor’easter that’s bringing accumulating snow to interior New England could bring some showers later today. Otherwise partly sunny with high temperatures on the cool side in the low-50s with northwesterly winds keeping a cap on temps. Overnight lows in the low-40s as rain chances die down.

Weather Prediction Center surface forecast for 8AM Saturday. Low pressure off of New England will be pulling to the east, but still close enough to give us some clouds.

Saturday – partly sunny with high temperatures in the upper-50s. Overnight lows in the upper-40s. Weak high pressure should keep any rain at bay.

Sunday – mostly cloudy, with high temperatures warming into the low-60s. Slight chance for showers in the afternoon. Overnight lows in the mid-40s.

GFS model 500 mb height and vorticity for Monday at 8AM. A fairly potent area of vorticity (dark purples) associated with a shortwave could bring some showers to the area.

Monday – mostly sunny to start with high temperatures in the mid-60s. Rain chances pick up in the afternoon with diurnally driven showers that could get a boost from some mid-level vorticity. Overnight lows at or slightly below 50ºF.

NYC Weather Update – Mar 1, 2021

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March brings in week of great contrasts, typical of a transition into spring. Periods of rain off and on today before a plunge in temperatures going into Tuesday. Strong northwesterly winds will accompany the cold as the pressure gradient tightens around the departing low bringing rain today. Temps rebound into the upper-40s midweek but drop back towards end of week into the upper-30s.

Rest of today – periods of rain mostly before noon. Breezy with northwest winds increasing into the 15-20 mph by later in the day. Temperatures start dropping with these winds kicking in after noon bringing on strong cold air advection. Clouds clear towards the overnight when lows are expected to drop into low-20s.

GFS model 2-meter above ground level temperatures, and 10-meter above ground level winds at 7AM Tuedsay.

Tuesday – mostly sunny with high temperatures in the mid-30s. Strong northwest winds in the 20-30 mph range with gusts above 45 mph possible. Overnight lows in the low-30s.

Wednesday – high temperatures rebound quickly to near 50ºF with winds subsiding and mostly sunny skies. Overnight temperatures dropping into the mid-30s.

GFS model surface precipitation, and 1000-500 mb thickness for Thursday at 11AM. The blue thickness lines over much of the northeast indicate a return to below normal temperatures on the way.

Thursday – temperatures cooling a touch back into the mid-40s with mostly sunny skies. Overnight lows dropping back into the upper-20s.

NYC Weekend Weather – Jan 29, 2021

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An arctic chill with bitterly cold winds kicks off the weekend as strong high pressure moves in. Overnight lows in the teens and high temperatures in the 20s will range 10-15ºF below normal for this time of year. This cold air could set the stage for a nor’easter bringing significant snowfall to the region, with totals > 6″ possible Monday into Tuesday. As usual, track details on this storm will be pivotal, and are not clear at this time.

Rest of today – mostly clear, cold, and windy with high temperatures in the low-20s. A strong arctic high and a departing low will create a tight pressure gradient that ushers in stiff northwesterly winds 20-25 mph. Wind chills will hover around 0ºF. Overnight temperatures drop into the mid-teens with wind chills likewise dropping below zero.

Weather Prediction Center surface forecast for 7AM Saturday. A strong area of high pressure is parked over much of the Eastern US.

Saturday – winds abate with high pressure moving more directly overhead. Sunny, but still cold with high temperatures around 30ºF. Overnight lows will be in the upper-teens under increasing cloud cover.

Sunday – mostly cloudy as the next storm system starts to work in. High temperatures around 30ºF. Overnight lows in the upper-20s with the possibility of snow developing overnight into Monday morning.

  • GFS model total snowfall accumulation as of 7AM Tuesday
  • ECMWF model total snowfall accumulation as of 7AM Tuesday
  • UKMET model total snowfall accumulation as of 7AM Tuesday

Monday – stiff northeasterly winds developing along with snow. High temperatures in the low-30s. The storm possibly bringing us significant snow came ashore over the west coast yesterday and will be transiting the country the next couple days. It is eventually forecast to spawn a coastal low, bringing a nor’easter into our region. Even though cold air will precede this storm, offshore waters are still mild, in the low 40s-50s, and with the storm likely to bring southerly/northeasterly flow at the outset, we could see enough warming to mix to rain at the coast. Storm track and strength will be vital to the eventual snowfall totals. Models seem to signal a very tight banding feature bringing heavy snow – you’ve heard this before but these bands are notoriously difficult to pinpoint even a day ahead of the event. If the optimal scenario plays out, we could see a storm with similar or possibly bigger totals than the one in December. Overnight lows Monday shouldn’t budge much, in the low-30s, with some warm advection associated with portions of the storm.

NYC Weekend Weather – Jan 22, 2021

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A cold and breezy start to the weekend with a cold front ushering in below average temperatures mostly in the mid-30s. High pressure builds and keeps things dry during the weekend. However, the upper-level pattern shifts to allow a shortwave trough to push through early next week, leading to a storm that could bring some accumulating snow overnight Monday into Tuesday.

Rest of today – partly cloudy with high temperatures in the low-40s. A moisture-starved cold front will work its way through the region. The main impact of this front will be to induce a shift in winds to the northwest, and trigger some decent cold air advection. This will lead to overnight temperatures plummeting into the mid-upper 20s.

Weather Prediction Center surface forecast for 7AM Saturday

Saturday – high pressure builds in behind the cold front, giving us a mostly sunny day. This high pressure and a low off to the northeast over the Canadian Maritimes will lead to a fairly tight pressure gradient, and the result should be breezy winds from the northwest, sustained in the range of 15-20 mph at least. So despite the sun, the cold start to the day will lead to temperatures in the low-30s and a much colder feel with wind chills around 20ºF. Overnight lows will be the coldest in quite some time, in the low-20s.

Sunday – windy conditions continue at least part of the day with high temperatures in the mid-30s. Once the center of the high moves over us, winds should subside. Overnight lows in the mid-20s with clouds building in.

GFS model 500 mb height and vorticity animated loop valid 7PM Sunday through 7PM Monday, showing a de-amplifying shortwave trough ejecting from the southwest towards our region.

Monday – as the high pressure eventually moves off, a shortwave trough will be progressing towards our region. The accompanying surface low will bring mostly cloudy skies. Temperatures should peak in the mid-30s. Overnight, the storm is positioned to possibly bring us some light accumulating snow. Currently, it’s hard to pin down a total, but the following images from GFS and ECMWF models suggest something on the order of 3-5″ is possible. Low temperatures in the upper-20s should support all snow during this event, so storm track will be key here.

  • GFS model 24 hour snowfall total ending 1AM Wednesday
  • ECMWF model total snowfall ending 1AM Wednesday

NYC Weekend Weather – Jan 15, 2021

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Our extended period of calm weather comes to an abrupt end this weekend. A low pressure system with its attendant vigorous cold front sweeps through overnight bringing moderate to heavy rain. We could see as much as 1-1.5″ of rain with this event. Behind this front, windy conditions prevail Sunday as the low exits but continues to deepen. Next week, we’ll see a return to normal temps around 40ºF.

Rest of today – mostly cloudy with high temperatures in the mid-40s. Rain chances increase as the storm system approaches us. Warm air advection associated with the warm front of this storm will result in little movement on overnight lows, which will hover in the mid-40s. Moderate to heavy rain is likely after 9PM tonight and into the overnight hours.

High Resolution Rapid Refresh simulated radar for 1AM Saturday.

Saturday – as the storm pulls off to the east in the morning, rain chances should decrease, ending by noon. Isolated wrap around showers are possible. Temperatures will decrease during the day with cold air advection, dropping into the low-40s. Overnight lows in the mid-30s as skies clear.

Sunday – mostly sunny with high temperatures in the low-40s. Breezy with west winds in the 15-20 mph range and stronger gusts due to a large pressure gradient around the exiting and intensifying low. Overnight lows in the mid-30s.

Weather Prediction Center surface forecast for 7AM Sunday. The low affecting us this weekend is seen in the upper right corner, with a tight clustering of isobars around it, indicating a large pressure gradient.

Monday – an upper level low will affect the area pushing a cold front through our region, but this front should be moisture starved. Partly sunny with highs around 40ºF. Overnight lows around 30ºF.

NYC Father’s Day Weekend Weather – Jun 19, 2020

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A slow moving low pressure and upper level low will result in the potential for isolated thunderstorms through the weekend with temperatures in the low-80s. Best chances for these diurnally driven thunderstorms would be in the afternoon hours. There’s a good amount of moisture in the air this weekend with steady southerly flow, so these storms could produce heavy rain, though severe weather is not anticipated. Past this weekend, a warmup to the mid-upper-80s (90s in interior) is forecast as upper level ridging and high pressure builds next week.

Saturday – fog early with cooler, marine flow. Temperatures warm into the low-80s with chances for scattered showers and thunderstorms particularly north and west of the city. Overnight lows in the upper-60s.

Weather Prediction Center surface forecast for 8AM Sunday

Sunday – Similar pattern to Saturday with partly sunny skies, isolated showers and thunderstorms developing later in the day particularly west of the city. Overnight lows in the upper-60s.

Monday – this pattern persists with partly sunny skies, highs in the low-80s and chances for isolated PM thunderstorms. Overnight lows in the low-70s.

GFS model 500 mb temperature, height, and wind forecast for 8PM Tuesday

Tuesday – high pressure builds offshore, with upper level ridging and 500 mb temperatures increasing, we should see sunny skies and very warm temperatures nearing 90ºF. Overnight lows in the mid-70s.

NYC Weekend Weather – May 1, 2020

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April ended with another stormy week with plenty of rain. May starts of grey Friday, followed by a spectacular day Saturday. Rain enters the picture again Sunday. Behind this next storm system, things will cool off again. This will lead temperatures to continue their cool trend throughout most of next week. During this period high temperatures will range at least 5ºF below the upper-60s that are normal for this time of the year.

Rest of today – the slow moving storm that began impacting us yesterday continues to influence weather today. Scattered showers wrapping around the backside of the low responsible for this storm could still occur. Temperatures should generally be in the low-60s with mostly cloudy skies otherwise. Overnight lows in the low-50s as the storm finally exits.

Weather Prediction Center surface forecast for 8AM Saturday

Saturday – high pressure builds in behind this storm, bringing the best day of the frorecast period with high temperatures expected to top out around 70ºF under sunny skies. Overnight lows in the mid-50s.

Sunday – just like last weekend, the sunny, dry weather barely lasts before the next storm moves in. This will be a weaker, and faster moving storm so rain should be on the lighter side. Currently expecting most of the day Sunday to be dry with clouds building and high temperatures still warm in the low-70s. Overnight lows in the mid-50s.

Monday – once this low clears our region, winds shift to the north and a cooler air mass works its way in. Skies clear with temperatures falling back the low-60s. Overnight lows only in the upper-40s. This cool trend looks set to continue for the duration of next week. Though after a week with high temperatures in the 50s, the low-60s looks pretty good.

  • Climate Prediction Center temperature outlook for May 6-10. Below average temperatures are indicated as very likely for much of the Eastern US
  • This temperature trend is borne out in the GFS models 2-meter above ground level temperature anomalies. This chart is valid for 8AM Tuesday

NYC Weather Update – Apr 27, 2020

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An active weather pattern brings yet another week of cool, rainy weather. Tuesday will be the only day with sunny skies and near normal temperatures with high pressure briefly building in. Otherwise, a couple slow moving storms will bring clouds and rain the rest of the week. This will result in temperatures largely running below seasonal averages. I suppose that’s some incentive for people to stay safe and quarantine at home?

Rest of today – early rain chances should diminish steadily. High temperatures cool, only around 50ºF under the influence of northerly flow as the slow moving coastal storm that impacted us yesterday and today moves off to the northeast. Clouds should start to diminish later in the day. Overnight lows in the low-40s.

NAM output forecast cloud cover for 11AM Tuesday

Tuesday – we should see a brief window of sunny skies and dry weather as high pressure builds and passes over for the day. This break in rainy weather should allow temperatures to climb into the low-60s. Overnight lows in the mid-40s.

Wednesday – the reprieve from dreary conditions barely lasts a day as yet another storm system takes aim at the area. With the high pressure Tuesday slow to move east, this next storm will be similarly as slow moving as this past weekend’s storm. The result for Wednesday, even if we don’t get too much in the way of rain, will be cloudy conditions and cool, southeasterly onshore flow ahead of an advancing warm front. This will cause temperatures to cool into the mid-50s. Overnight lows barely budge, and hover around 50ºF.

Weather Prediction Center surface forecast for 8AM Thursday

Thursday – the second storm of the week hits with steady rain and southeasterly onshore breezes. Warm advection could help temperatures stay slightly above 60ºF, with overnight lows in the low-50s.

NYC Weekend Weather – Apr 24, 2020

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Two coastal lows bring will rain today and Sunday. Saturday ends up being a nice day in between with some high pressure building briefly. The second coastal storm coming on Sunday drags into Monday bringing rain and cool temperatures. Throughout this period, temperatures will range at least 5ºF below normal. This below normal temperature trend, largely a continuation of this week, looks set to continue well into next week.

Rest of today – high temperatures in the low-50s with cloudy conditions and periods of steady rain off and on for much of the day. Overnight lows in the low-40s with rain winding down and clouds clearing.

Saturday – sunny skies and high pressure should allow temperatures to climb to about 60ºF. Overnight lows in the mid-40s.

Weather Prediction Center surface forecast for 8AM Sunday

Sunday – unfortunately, the dry weather doesn’t last as a second storm moves in for Sunday, bringing yet more rain and cool, cloudy weather. High temperatures topping out only in the low-50s. Overnight lows in the low-40s.

Monday – high temperatures still suppressed in the low-50s as this second storm lifts to the east. Overnight lows in the low-40s. Going into next week, temperature will stay below normal, anywhere between 5-10ºF. Later in the week, it appears a potent, closed 500 mb low will be the culprit for keeping temperatures down (and bringing yet more rain to us)

  • Climate Prediction Center temperature outlook for Apr 29-May 3, showing below average temperatures continuing to affect much of the northeastern quadrant of the US
  • GFS 500 mb temperature, height and winds for 2AM Thursday, Apr 30. A closed 500 mb low is forecast to move over the Great Lakes and southern Ontario – this will be partly responsible for cooler than normal temperatures.